1. Field of the Invention
The present invention relates to remote control systems, remote controllers, information processing apparatuses, remote control methods, information processing methods, and computer programs therefore. More particularly, the present invention relates to a remote control system or the like capable of controlling, using a remote controller, an information processing apparatus in accordance with the distance from the remote controller to the information processing apparatus.
2. Description of the Related Art
Many of known remote controllers including, for example, television remote controllers are equipped with a button (cross key or the like) for instructing the up, down, left, and right directions. A user uses the button to give an instruction to an information processing apparatus, such as a television, to be controlled. For example, the user can instruct the up, down, left, and right directions using the button of the remote controller and select a desired item from among a plurality of items included in a menu displayed on a display screen of the information processing apparatus.
As has been described above, the user can easily give a two-dimensional instruction, such as movement in the x-axis (horizontal) direction and the y-axis (vertical) direction to a selection item, using the known remote controller described above. However, when the user wants to select one of a nearby image positioned near the user (foreground) and an image positioned far away from the user (background), it is necessary to use a remote controller capable of giving an instruction in the z-axis direction (foreground and background). Current information processing apparatuses are equipped with, in addition to a button indicating the x- and y-axes directions, a button or a lever instructing the z-axis direction, thereby being able to give an instruction in the z-axis direction.
However, when the user uses the button to give an instruction in the z-axis direction, the user has difficulty in understanding the relationship between the foreground/background directions and the button, and it is thus difficult for the user to give an intuitive instruction, as in the case of the x- and y-axes directions. When the user uses the lever to give an instruction in the z-axis direction, the user can associate the foreground/background directions with the directions in which the lever is tilted (or moved). Accordingly, the user can give an instruction more easily than with the button. However, the lever only allows the user to instruct either the foreground or the background direction. Therefore, when the user wants to perform various operations on the information processing apparatus, it is necessary for the user to use the lever in combination with other buttons or the like to give the associated instructions, which is complicated.
A system for allowing an information processing apparatus to execute a predetermined operation in accordance with the distance between a remote controller and the information processing apparatus has been proposed (for example, see Japanese Unexamined Patent Application Publication No. 2003-140630). According to this display system, the distance between a television and a remote controller is measured upon pressing a button of the remote controller, and the size of an icon displayed on the television is changed according to the measured distance. Also, an apparatus for converting a hand motion of a user into three-dimensional positional information and executing an operation associated with the motion has been proposed (for example, see Japanese Unexamined Patent Application Publication No. 2004-341892). According to this instruction input apparatus, a hand motion of a user in the z-axis direction is detected, and, when the hand motion coincides with a predetermined motion, it is determined that the user has performed an operation associated with the motion, such as clicking, double-clicking, or dragging.